Investigation on Several Methods for Testing Cathodic Protection Parameters

Performance of insulation joint (flange) and in-pipe current are important data of cathodic protection parameters. The various methods recommended in GB/T 21246-2007 were adopted to study the insulation performance and current test of Jingbian gathering and transportation pipeline system in Changqing oilfield. Through data analysis, combined with numerical analysis and error analysis, the recommended test methods in the national standard were analyzed and discussed. The results show that the potential method and PCM leakage rate method are suitable for insulation performance test of in-service insulated joints (flanges), and the combination of the two methods can improve the accuracy of measurement. Due to the inaccuracy of instrument measurement, leakage resistance method and grounding resistance measurement instrument method are not suitable for insulation performance test of insulated joints (flanges). Voltage drop method and calibration method are applicable to the measurement of current in the pipe. Some useful suggestions for the field application of these methods are put forward.